| From 9dc20113988b9a75ea6b3abd68dc45e2d73ccdab Mon Sep 17 00:00:00 2001 |
| From: Yifeng Li <tomli@tomli.me> |
| Date: Tue, 2 Apr 2019 17:14:10 +0200 |
| Subject: fbdev: sm712fb: fix memory frequency by avoiding a switch/case fallthrough |
| |
| From: Yifeng Li <tomli@tomli.me> |
| |
| commit 9dc20113988b9a75ea6b3abd68dc45e2d73ccdab upstream. |
| |
| A fallthrough in switch/case was introduced in f627caf55b8e ("fbdev: |
| sm712fb: fix crashes and garbled display during DPMS modesetting"), |
| due to my copy-paste error, which would cause the memory clock frequency |
| for SM720 to be programmed to SM712. |
| |
| Since it only reprograms the clock to a different frequency, it's only |
| a benign issue without visible side-effect, so it also evaded Sudip |
| Mukherjee's code review and regression tests. scripts/checkpatch.pl |
| also failed to discover the issue, possibly due to nested switch |
| statements. |
| |
| This issue was found by Stephen Rothwell by building linux-next with |
| -Wimplicit-fallthrough. |
| |
| Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> |
| Fixes: f627caf55b8e ("fbdev: sm712fb: fix crashes and garbled display during DPMS modesetting") |
| Signed-off-by: Yifeng Li <tomli@tomli.me> |
| Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> |
| Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com> |
| Cc: Kees Cook <keescook@chromium.org> |
| Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/video/fbdev/sm712fb.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| --- a/drivers/video/fbdev/sm712fb.c |
| +++ b/drivers/video/fbdev/sm712fb.c |
| @@ -898,6 +898,7 @@ static int smtc_blank(int blank_mode, st |
| case 0x712: |
| smtc_seqw(0x6a, 0x16); |
| smtc_seqw(0x6b, 0x02); |
| + break; |
| case 0x720: |
| smtc_seqw(0x6a, 0x0d); |
| smtc_seqw(0x6b, 0x02); |
